Process of making last-patterns of graduated sizes



NrTnn TATES WILLIAM KINGSTON, or LITTLE FALLS, ASSIGNOR To n. S. KINGSTON, OF UTIGA, NE YORK.

PROCESS OF MAKING LAST-PATTERNS OF GRADUATED SIZES.

:UPEGIFICATION forming part of Letters Patent No. 317,948, dated May 12, 1885.

Application filed June 12, 1884. (No model.)

To all whom it may concern:

Be it known that I, -WILLIAM KINGSTON, a citizen of the United States, residing at Little Falls, in the county of Herkimer and State of New York, have invented certain new and useful Improvements in the Manufacture of Iron Lasts; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawing, and to letters or figures of reference marked thereon, which form a part of this specification.

The invention is a new method of making patterns of graduated sizes, from which the iron lasts are cast, as will be hereinafter fully described and claimed. Iron lasts have commonly been cast in graduated sizes and of proper form, similar to those which I make by my process; but the mode of manufacturing being slow and expensive, iron lasts, although much more desirable than wooden lasts, have been but little used, and wooden ones have had the preference.

Heretofore, in making iron lasts, it has been necessary, first, to turn'a full set of wooden lasts, including all the sizes from the smallest to the largest. These wooden forms were then taken by pattern makers and carvers and hollowed out and fitted up to serve as patterns. Each one of these wooden patterns was used to form a mold in which, by casting, Was obtained a metal pattern. In this manner a full set of metal patterns, including each size and half-size, was obtained, and the wooden patterns, being of no further use, were thrown away. This slow and expensive way of making these wooden patterns has discouraged the manufacturer of iron lasts.

The object of this invention is to facilitate the manufacture of iron lasts by dispensing, for the most part, with wooden patterns.

In carrying out this invention I first make a pair of wooden patterns of proper shape, and of the largest size which is likely to be required, and from this single pair of wooden patterns I obtain by my process all the sizes in metallic patterns required. Having made and fitted up the first and largest pair of patterns of wood in the style required, I then with them make molds in Sand, or other known material capable of being molded, and in these molds I cast a pair of patterns by pouring into them what is known as non-shrinking pattern metal, which is a composition of lead, tin, zinc, and antimony. This pair of metallic patterns are similar in size and form to the wooden patterns, and having obtained them I have no further recourse to wooden patterns. By the aid of this first pair of patterns I now proceed to get patterns of all the other sizes required in the following manner: A composition of copper and tin is made, and when melting the same a hardening, consisting of tin and zinc, is added. This metal is commonly known as bronze, and it sh rinks in cooling. The metal prepared should, like the bronze, shrink in cooling sufficiently to reduce a pattern cast in such metal in cooling a degree known as half-size in last-making. Having prepared this metal and made molds in sand or other moldable material by using the patterns already cast of the non-shrinking metals already referred to, I cast in these molds a pair of patterns of the shrinking metal, and the result is, that a pair of patterns is obtained which is a hal f-size smaller than the first pair. In a similar manner a third pair of patterns is obtained from the second pair, which is just halfsize smaller than the pair they were cast from. By similar proceedings I obtain in the shrinking metal all the sizes of last-patterns required, down to the smallest, and from these patterns the iron lasts are cast in the usual manner.

In making the shrinking metallic composition the proportions of the ingredients preferred are as follows: For the middle sizes a compound of copper and tin, in the propor- 0 tion of about six parts, by weight, of the former to one part of the latter, to which one part of zinc and a half part of tin are added as a hardening, answers an excellent purpose. For the smaller sizes, what is known in the art as 5 yellow brass will serve, and for the largest sizes iron will be found to be capable of a reduction by shrinkage and finishing off, which will suffice for the half-size required.

Having described this invention, what I IOO claim, and desire to secure by Letters Patent, 1s

1. The process of forming last-patterns in graduated sizes, which consists in making in any known way a pair of last-patterns of the largest size required, in using these patterns to form molds, in casting in these molds a me tallic composition which will shrink half a size in cooling, thereby producing patterns one-half size smaller than the original patterns, and using these smaller patterns to obtain in the same Way, through molds, patterns ahalf-size smaller, and so on until the desired number of sizes of patterns have been obtained, substantially as set forth.

2. The process of making lasts in graduated sizes, which consists in forming a metallic pattern of the largest size required, and from this pattern producing successive patterns of material which will shrink half a size in casting through the medium of molds, each pat tern, as formed, serving to prepare the mold for the next smaller pattern required.

In testimony whereof I affix my signature in presence of two Witnesses.

WM. KINGSTON. 

